<div class="indent">5.5 -
<a href="#5.5">Why is FlightGear so slow?</a>
</div>
- <div class="indent">5.6 -
- <a href="#5.6">Why is my SGI machine so slow?</a>
- </div>
<div class="indent">5.7 -
<a href="#5.7">How do I see the frame rate?</a>
</div>
like <i>Quake3</i>.</p>
</div>
- <b>
- <a name="5.6">5.6 -
- <u>Why is my SGI machine so slow?</u>
- </a>
- </b>
- <div class="indent">
- <p>First of all, one of the most common mistakes on SGI hardware is to
- forget to specify --fog-fastest. On most SGI machines the EXP2 shading
- model isn't hardware supported resulting in frame rates below 1 frame
- per second (fps).</p>
- <p>FlightGear makes extensive use of the OpenGL z-buffer feature,which
- on most older SGI hardware is only supported in software. This means
- that the CPU has to do all the z-buffer calculations in addition to the
- other tasks FlightGear involves (flight dynamics, scenery tracking,
- pushing commands into the graphics queue, etc). The following features
- are software rendered on low-end SGI machines (like Indy and
- Indigo):</p>
- <ul>
- <li>stencil and accumulation buffer</li>
- <li>depth queuing and depth buffering</li>
- <li>fogging, lighting, clipping and transforms</li>
- <li>texturing</li>
- </ul>
- <p>This means that running FlightGear with the following options may not
- even get the desired result:</p>
- <p>
- <code>./runfgfs --fog-disable --shading-flat --disable-skyblend \</code>
- <br>
- <code>--disable-textures --disable-clouds --disable-sound \</code>
- <br>
- <code>--disable-panel --enable-hud --disable-anti-alias-hud</code>
- </p>
- <p>I could even imagine that adding --enable-wireframe doesn't work on
- these machines (I would be happy to be proven wrong though).</p>
- <p>On a machine like O2 the following options give an acceptable
- result:</p>
- <code>./runfgfs --fog-fastest --disable-sound</code>
- <p>Since I don't have access to other SGI hardware I can't tell which
- options would be appropriate for your situation.</p>
- </div>
-
<b>
<a name="5.7">5.7 -
<u>How do I see the frame rate?</u>